node-red-node-piface
====================

<a href="http://nodered.org" target="_new">Node-RED</a> nodes to control a <a href="http://www.piface.org.uk/products/piface_digital/" target="_new">PiFace Digital</a> add-on board for a Raspberry-Pi.

Install
-------

Run the following command in the root directory of your Node-RED install

    npm install node-red-node-piface


Pre-reqs
--------

Requires the WiringPi gpio command to be installed in order to work. See the <a href="http://wiringpi.com" target="new">WiringPi site</a> for details on how to do this.


Usage
-----

A pair of input and output Node-RED nodes for the Raspberry Pi PiFace Digital add-on board.

###Output

The PiFace output node will set the selected relay, LED, or pin on or off depending on the value passed in. Expects a <b>msg.payload</b> with either a 1 or 0 (or true or false).

Requires the WiringPi gpio command in order to work (see pre-reqs).

###Input

The PiFace input node generates a <b>msg.payload</b> with either a 0 or 1 depending on the state of the input pin.

You may also enable the input pullup resistor if required.

The <b>msg.topic</b> is set to <i>piface/{the pin number}</i>

Requires the WiringPi gpio command in order to work (see pre-reqs).

<b>Note:</b> This node currently polls the pin every 250mS. This is not ideal as it loads the cpu.